Dec 6, 2016

Plants Are Even Smarter Than We Thought

Can plants learn by forming associations? They can, if you ask researchers from The University of Western Australia (WA), who say they've shown for the first time that plants can link events to learn more about their surroundings and use the associations to better their chances of survival.

The researchers focused their study on the garden pea Pisum sativum, seedlings of which they placed at the base of a Y-shaped maze. Then, in a series of training sessions, they put a fan and a light source at the end of either the same arm or opposing arms of the Y.

According to the scientists, the seedlings became better seekers of precious light by learning to associate the breeze of the fan with the location where the light would shine, growing toward that location even when the light was removed.

"The ability of seedlings to anticipate both the imminent arrival of light ('when') and its direction ('where') based on the presence and position of the fan indicates that plants are able to encode both temporal and spatial information and modify their behavior under the control of environmental cues," the scientists wrote.

The team suggested that the type of learning demonstrated by the seedlings should no longer be considered exclusive to the animal kingdom: "Our results show that associative learning is an essential component of plant behavior. We conclude that associative learning represents a universal adaptive mechanism shared by both animals and plants."

"Whilst the possibility that plants also learn by association has been considered by earlier studies," the scientists added, "our current study provides the first unequivocal evidence."

The WA scientists said they're aware of how their "smart plant" discoveries might be interpreted.

"Because our findings are unexpected, we anticipate that this study will stir a lively and exciting debate on the origin and properties of memory, learning and ultimately intelligent behavior in biological systems," said study lead Monica Gagliano, in a statement.

The researchers say their study was inspired by Russian scientist Ivan Pavlov's famed research on conditioned responses in dogs, which explored how behavior could be modified through conditioning.

Gagliano and her team have documented their findings in the online journal Scientific Reports.